March 18, 2013 As soon as you enter, QUIETLY and QUICKLY 1. Read the F.Q. and L.G.’s. 2. Answer...

March 18, 2013March 18, 2013As soon as you enter, As soon as you enter, QUIETLY and QUICKLYQUIETLY and QUICKLY

1.1.Read the Read the F.Q.F.Q. and and L.G.’sL.G.’s..2.2. Answer the Answer the L.P.L.P.

3.3.Receive a stamp!Receive a stamp!You have 4 minutes.You have 4 minutes.

WeatheringWeathering is is the physical and the physical and chemical changes in rocks at Earth’s chemical changes in rocks at Earth’s surfacesurface..

Copyright © 2010 Ryan P. Murphy

The The 2 types of weathering2 types of weathering are are physicalphysical and and chemical.chemical.


Physical weathering Physical weathering is breaking is breaking rocks into smaller pieces rocks into smaller pieces without a without a change in compositionchange in composition..


Agents of physical weathering Agents of physical weathering includeinclude HeatHeat WaterWater IceIce PressurePressure


Agents of physical weathering Agents of physical weathering includeinclude HeatHeat WaterWater IceIce And PressureAnd Pressure


AbrasionAbrasion – the – the grinding away of rock by friction with other rocks with other rocks


• What is exfoliation in the beauty world?

“It’s when you remove dead skin

cells so new healthy cells are shown.”

Sheeting/ ExfoliationSheeting/ Exfoliation – rock layers – rock layers peel off, fall, and break apartpeel off, fall, and break apart..


• Exfoliation is much like an onion losing layers.


• Which picture best represents exfoliation?


• Answer! A.

• Answer! A. B is ice wedging.

• Which picture best represents exfoliation?


• Answer! B.


• Answer! B. A is Chemical Weathering.


• What happens if you leave a can of soda in the freezer?

• ANSWER: The can will explode because water expands when it is frozen.


• The increase in volume of ice is about 9%.


• The increase in volume of ice is about 9%. This increase causes enough force to break most rigid containers.


• The increase in volume of ice is about 9%. This increase causes enough force to break most rigid containers. This is the same force, repeated on a daily basis, that creates cracks in the roads in the winter.


Frost Wedging Frost Wedging – water enters – water enters cracks in rocks, cracks in rocks, freezes, expands,freezes, expands, and breaks rocks.and breaks rocks.


Frost wedging creates cracks and holds which you can use to rock climb!


• What is this a picture of?

• What is this a picture of?• Answer: This is a picture of the Old Man of

the Mountain in New Hampshire!

Thermal Expansion – repeated heating and cooling of rocks results in stress and breakage.


• Which is exfoliation, and which is thermal expansion?

A B


• Answer! Trick Question. Thermal expansion leads to sheeting / exfoliation.

A B


Root WedgingRoot Wedging – Plant roots enter a – Plant roots enter a crack, crack, grow and expand the crackgrow and expand the crack..


• Which picture best represents ice wedging, and which picture best represents root wedging?


Root Wedging


Root Wedging Frost Wedging


Animal ActivityAnimal Activity – Animals – Animals mechanicallymechanically wear away the rock. wear away the rock.


Wind weatheringWind weathering – particles of sand, – particles of sand, pebbles, and dust pebbles, and dust are carried by wind are carried by wind and cause abrasionand cause abrasion..


March 21, 2013March 21, 2013As soon as you enter, As soon as you enter, QUIETLY and QUICKLYQUIETLY and QUICKLY

1.1.Copy the Copy the F.Q.F.Q. and and L.G.’sL.G.’s in in your NOTEBOOK.your NOTEBOOK.

2.2.List as many examples of List as many examples of weathering as you can.weathering as you can.

3.3.Receive a stamp!Receive a stamp!You have 4 minutes.You have 4 minutes.

Chemical Weathering Chemical Weathering occurs when occurs when chemical processes break down chemical processes break down rocksrocks and change their composition. and change their composition.


Chemical weathering rate depends Chemical weathering rate depends onon

TemperatureTemperature Amount of surface areaAmount of surface area Availability of water or natural acidAvailability of water or natural acid


Chemical weathering rate depends Chemical weathering rate depends onon

TemperatureTemperature Surface areaSurface area Availability of water or natural acidAvailability of water or natural acid


CarbonationCarbonation – Water and CO – Water and CO2 2 create create carbonic acidcarbonic acid which wears which wears down rock. down rock.


• Brought to New York City • Water + Chemical Pollution =


HydroHydrolysis –lysis –


HydrolysisHydrolysis – Chemical reaction – Chemical reaction between the between the minerals in the rock and minerals in the rock and hydrogenhydrogen in rain water wears down in rain water wears down rock.rock.


OxidationOxidation – The process by which – The process by which oxygen combines with wateroxygen combines with water and and minerals in the rock to weaken it.minerals in the rock to weaken it.


• Which picture best represents oxidation weathering?


• Answer! B.


• Answer! B. A appears to by more hydrolysis than oxidation.


SolutionSolution – Process by which – Process by which minerals in the rocks minerals in the rocks dissolve directly dissolve directly in waterin water..


LIMESTONE CAVES


Hydration – Hydration – Process where Process where minerals in the rock absorb waterminerals in the rock absorb water and expand.and expand.


Salts as well as organic acids in soil Salts as well as organic acids in soil and from plant like lichensand from plant like lichens cause cause chemical weathering.chemical weathering.


March 22, 2013As soon as you enter, QUIETLY and QUICKLY

1.Copy the F.Q. and L.G.’s in your NOTEBOOK.

2.List as many examples of weathering as you can.

3.Receive a stamp!You have 5 minutes.

What is this a picture of? How long will it be there?


Answer: This is a photograph of a footprint on the moon made in 1969. It is most likely still there.

Why?

• Weathering occurs very quickly on Earth because of wind, water, and animals.


• The moon does NOT have an ATMOSPHERE—most important agent of weathering!


HOW DOES THE ENVIRONMENT AFFECT WEATHERING?

• The harder a rock is, the more it RESISTS weathering.

• The more chemically stable a rock’s minerals are, the more it RESISTS weathering.

SURFACE AREA MATTERS!

HOW DOES THE ENVIRONMENT AFFECT WEATHERING?

• The colder the climate, the more likely PHYSICAL WEATHERING will occur.

• The warmer and wetter the climate, the more likely CHEMICAL WEATHERING will occur.

PRACTICE QUESTIONS1. You found several rocks weathered by

wind-blown sand in a desert environment. These angular rocks are called ventifacts. What kind of weathering process most likely shaped these rocks?

A. Physical abrasionB. Chemical weatheringC. Biological processesD. Melting of rock

PRACTICE QUESTIONS1. You found several rocks weathered by

wind-blown sand in a desert environment. These angular rocks are called ventifacts. What kind of weathering process most likely shaped these rocks?

A. Physical abrasion

PRACTICE QUESTIONS2. What kind of weathering are carbonation

and hydrolysis?A. PhysicalB. BiologicalC. ChemicalD. Glacial

PRACTICE QUESTIONS2. What kind of weathering are carbonation and hydrolysis?

C. Chemical

PRACTICE QUESTIONS3. What substance combines with atmospheric gases to cause hydrolysis and carbonation?

A. Potassium feldsparB. AirC. Hydrochloric acidD. Water

PRACTICE QUESTIONS3. What substance combines with atmospheric gases to cause hydrolysis and carbonation?

D. Water

PRACTICE QUESTIONS4. What kind of weathering is most common

in an area with an average yearly temperature of 5ºC and precipitation of 45 cm?A.Moderate chemical weatheringB.Very slight weathering C.Moderate chemical weathering with frost actionD.Slight frost action

PRACTICE QUESTIONS4. What kind of weathering is most common

in an area with an average yearly temperature of 5ºC and precipitation of 45 cm?

D. Slight frost action

WHY IS WEATHERING IMPORTANT?

• Because it creates SOIL and soil leads to LIFE!

• Soil = a mixture of weathered rock and organic matter.

Relationship of Transported Particle Size to Water Velocity

PRACTICE QUESTIONS

Complete # 8-13 on page 70.

You have 10 minutes!

March 18, 2013 As soon as you enter, QUIETLY and QUICKLY 1. Read the F.Q. and L.G.’s. 2. Answer...

Documents

Transcript of March 18, 2013 As soon as you enter, QUIETLY and QUICKLY 1. Read the F.Q. and L.G.’s. 2. Answer...